/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <ipxe/uaccess.h>
#include <ipxe/init.h>
#include <ipxe/profile.h>
#include <ipxe/netdevice.h>
#include <rmsetjmp.h>
#include <registers.h>
#include <biosint.h>
#include <pxe.h>
#include <pxe_call.h>
/** @file
*
* PXE API entry point
*/
/* Disambiguate the various error causes */
#define EINFO_EPXENBP \
__einfo_uniqify ( EINFO_EPLATFORM, 0x01, \
"External PXE NBP error" )
#define EPXENBP( status ) EPLATFORM ( EINFO_EPXENBP, status )
/** Vector for chaining INT 1A */
extern struct segoff __text16 ( pxe_int_1a_vector );
#define pxe_int_1a_vector __use_text16 ( pxe_int_1a_vector )
/** INT 1A handler */
extern void pxe_int_1a ( void );
/** INT 1A hooked flag */
static int int_1a_hooked = 0;
/** Real-mode code segment size */
extern char _text16_memsz[];
#define _text16_memsz ( ( size_t ) _text16_memsz )
/** Real-mode data segment size */
extern char _data16_memsz[];
#define _data16_memsz ( ( size_t ) _data16_memsz )
/** PXENV_UNDI_TRANSMIT API call profiler */
static struct profiler pxe_api_tx_profiler __profiler =
{ .name = "pxeapi.tx" };
/** PXENV_UNDI_ISR API call profiler */
static struct profiler pxe_api_isr_profiler __profiler =
{ .name = "pxeapi.isr" };
/** PXE unknown API call profiler
*
* This profiler can be used to measure the overhead of a dummy PXE
* API call.
*/
static struct profiler pxe_api_unknown_profiler __profiler =
{ .name = "pxeapi.unknown" };
/** Miscellaneous PXE API call profiler */
static struct profiler pxe_api_misc_profiler __profiler =
{ .name = "pxeapi.misc" };
/**
* Handle an unknown PXE API call
*
* @v pxenv_unknown Pointer to a struct s_PXENV_UNKNOWN
* @ret #PXENV_EXIT_FAILURE Always
* @err #PXENV_STATUS_UNSUPPORTED Always
*/
static PXENV_EXIT_t pxenv_unknown ( struct s_PXENV_UNKNOWN *pxenv_unknown ) {
pxenv_unknown->Status = PXENV_STATUS_UNSUPPORTED;
return PXENV_EXIT_FAILURE;
}
/** Unknown PXE API call list */
struct pxe_api_call pxenv_unknown_api __pxe_api_call =
PXE_API_CALL ( PXENV_UNKNOWN, pxenv_unknown, struct s_PXENV_UNKNOWN );
/**
* Locate PXE API call
*
* @v opcode Opcode
* @ret call PXE API call, or NULL
*/
static struct pxe_api_call * find_pxe_api_call ( uint16_t opcode ) {
struct pxe_api_call *call;
for_each_table_entry ( call, PXE_API_CALLS ) {
if ( call->opcode == opcode )
return call;
}
return NULL;
}
/**
* Determine applicable profiler (for debugging)
*
* @v opcode PXE opcode
* @ret profiler Profiler
*/
static struct profiler * pxe_api_profiler ( unsigned int opcode ) {
/* Determine applicable profiler */
switch ( opcode ) {
case PXENV_UNDI_TRANSMIT:
return &pxe_api_tx_profiler;
case PXENV_UNDI_ISR:
return &pxe_api_isr_profiler;
case PXENV_UNKNOWN:
return &pxe_api_unknown_profiler;
default:
return &pxe_api_misc_profiler;
}
}
/**
* Dispatch PXE API call
*
* @v bx PXE opcode
* @v es:di Address of PXE parameter block
* @ret ax PXE exit code
*/
__asmcall void pxe_api_call ( struct i386_all_regs *ix86 ) {
uint16_t opcode = ix86->regs.bx;
userptr_t uparams = real_to_user ( ix86->segs.es, ix86->regs.di );
struct profiler *profiler = pxe_api_profiler ( opcode );
struct pxe_api_call *call;
union u_PXENV_ANY params;
PXENV_EXIT_t ret;
/* Start profiling */
profile_start ( profiler );
/* Locate API call */
call = find_pxe_api_call ( opcode );
if ( ! call ) {
DBGC ( &pxe_netdev, "PXENV_UNKNOWN_%04x\n", opcode );
call = &pxenv_unknown_api;
}
/* Copy parameter block from caller */
copy_from_user ( ¶ms, uparams, 0, call->params_len );
/* Set default status in case child routine fails to do so */
params.Status = PXENV_STATUS_FAILURE;
/* Hand off to relevant API routine */
ret = call->entry ( ¶ms );
/* Copy modified parameter block back to caller and return */
copy_to_user ( uparams, 0, ¶ms, call->params_len );
ix86->regs.ax = ret;
/* Stop profiling, if applicable */
profile_stop ( profiler );
}
/**
* Dispatch weak PXE API call with PXE stack available
*
* @v ix86 Registers for PXE call
* @ret present Zero (PXE stack present)
*/
int pxe_api_call_weak ( struct i386_all_regs *ix86 ) {
pxe_api_call ( ix86 );
return 0;
}
/**
* Dispatch PXE loader call
*
* @v es:di Address of PXE parameter block
* @ret ax PXE exit code
*/
__asmcall void pxe_loader_call ( struct i386_all_regs *ix86 ) {
userptr_t uparams = real_to_user ( ix86->segs.es, ix86->regs.di );
struct s_UNDI_LOADER params;
PXENV_EXIT_t ret;
/* Copy parameter block from caller */
copy_from_user ( ¶ms, uparams, 0, sizeof ( params ) );
/* Fill in ROM segment address */
ppxe.UNDIROMID.segment = ix86->segs.ds;
/* Set default status in case child routine fails to do so */
params.Status = PXENV_STATUS_FAILURE;
/* Call UNDI loader */
ret = undi_loader ( ¶ms );
/* Copy modified parameter block back to caller and return */
copy_to_user ( uparams, 0, ¶ms, sizeof ( params ) );
ix86->regs.ax = ret;
}
/**
* Calculate byte checksum as used by PXE
*
* @v data Data
* @v size Length of data
* @ret sum Checksum
*/
static uint8_t pxe_checksum ( void *data, size_t size ) {
uint8_t *bytes = data;
uint8_t sum = 0;
while ( size-- ) {
sum += *bytes++;
}
return sum;
}
/**
* Initialise !PXE and PXENV+ structures
*
*/
static void pxe_init_structures ( void ) {
uint32_t rm_cs_phys = ( rm_cs << 4 );
uint32_t rm_ds_phys = ( rm_ds << 4 );
/* Fill in missing segment fields */
ppxe.EntryPointSP.segment = rm_cs;
ppxe.EntryPointESP.segment = rm_cs;
ppxe.Stack.segment_address = rm_ds;
ppxe.Stack.Physical_address = rm_ds_phys;
ppxe.UNDIData.segment_address = rm_ds;
ppxe.UNDIData.Physical_address = rm_ds_phys;
ppxe.UNDICode.segment_address = rm_cs;
ppxe.UNDICode.Physical_address = rm_cs_phys;
ppxe.UNDICodeWrite.segment_address = rm_cs;
ppxe.UNDICodeWrite.Physical_address = rm_cs_phys;
pxenv.RMEntry.segment = rm_cs;
pxenv.StackSeg = rm_ds;
pxenv.UNDIDataSeg = rm_ds;
pxenv.UNDICodeSeg = rm_cs;
pxenv.PXEPtr.segment = rm_cs;
/* Update checksums */
ppxe.StructCksum -= pxe_checksum ( &ppxe, sizeof ( ppxe ) );
pxenv.Checksum -= pxe_checksum ( &pxenv, sizeof ( pxenv ) );
}
/** PXE structure initialiser */
struct init_fn pxe_init_fn __init_fn ( INIT_NORMAL ) = {
.initialise = pxe_init_structures,
};
/**
* Activate PXE stack
*
* @v netdev Net device to use as PXE net device
*/
void pxe_activate ( struct net_device *netdev ) {
uint32_t discard_a;
uint32_t discard_b;
uint32_t discard_d;
/* Ensure INT 1A is hooked */
if ( ! int_1a_hooked ) {
hook_bios_interrupt ( 0x1a, ( intptr_t ) pxe_int_1a,
&pxe_int_1a_vector );
devices_get();
int_1a_hooked = 1;
}
/* Set PXE network device */
pxe_set_netdev ( netdev );
/* Notify BIOS of installation */
__asm__ __volatile__ ( REAL_CODE ( "pushw %%cs\n\t"
"popw %%es\n\t"
"int $0x1a\n\t" )
: "=a" ( discard_a ), "=b" ( discard_b ),
"=d" ( discard_d )
: "0" ( 0x564e ),
"1" ( __from_text16 ( &pxenv ) ) );
}
/**
* Deactivate PXE stack
*
* @ret rc Return status code
*/
int pxe_deactivate ( void ) {
int rc;
/* Clear PXE network device */
pxe_set_netdev ( NULL );
/* Ensure INT 1A is unhooked, if possible */
if ( int_1a_hooked ) {
if ( ( rc = unhook_bios_interrupt ( 0x1a,
( intptr_t ) pxe_int_1a,
&pxe_int_1a_vector ))!= 0){
DBGC ( &pxe_netdev, "PXE could not unhook INT 1A: %s\n",
strerror ( rc ) );
return rc;
}
devices_put();
int_1a_hooked = 0;
}
return 0;
}
/** Jump buffer for PXENV_RESTART_TFTP */
rmjmp_buf pxe_restart_nbp;
/**
* Start PXE NBP at 0000:7c00
*
* @ret rc Return status code
*/
int pxe_start_nbp ( void ) {
int jmp;
int discard_b, discard_c, discard_d, discard_D;
uint16_t status;
DBGC ( &pxe_netdev, "PXE NBP starting with netdev %s, code %04x:%04zx, "
"data %04x:%04zx\n", ( pxe_netdev ? pxe_netdev->name : "<none>"),
rm_cs, _text16_memsz, rm_ds, _data16_memsz );
/* Allow restarting NBP via PXENV_RESTART_TFTP */
jmp = rmsetjmp ( pxe_restart_nbp );
if ( jmp )
DBGC ( &pxe_netdev, "PXE NBP restarting (%x)\n", jmp );
/* Far call to PXE NBP */
__asm__ __volatile__ ( REAL_CODE ( "pushl %%ebp\n\t" /* gcc bug */
"movw %%cx, %%es\n\t"
"pushw %%es\n\t"
"pushw %%di\n\t"
"sti\n\t"
"lcall $0, $0x7c00\n\t"
"popl %%ebp\n\t" /* discard */
"popl %%ebp\n\t" /* gcc bug */ )
: "=a" ( status ), "=b" ( discard_b ),
"=c" ( discard_c ), "=d" ( discard_d ),
"=D" ( discard_D )
: "a" ( 0 ), "b" ( __from_text16 ( &pxenv ) ),
"c" ( rm_cs ),
"d" ( virt_to_phys ( &pxenv ) ),
"D" ( __from_text16 ( &ppxe ) )
: "esi", "memory" );
if ( status )
return -EPXENBP ( status );
return 0;
}
/**
* Notify BIOS of existence of network device
*
* @v netdev Network device
* @v priv Private data
* @ret rc Return status code
*/
static int pxe_notify ( struct net_device *netdev, void *priv __unused ) {
/* Do nothing if we already have a network device */
if ( pxe_netdev )
return 0;
/* Activate (and deactivate) PXE stack to notify BIOS */
pxe_activate ( netdev );
pxe_deactivate();
return 0;
}
/** PXE BIOS notification driver */
struct net_driver pxe_driver __net_driver = {
.name = "PXE",
.probe = pxe_notify,
};
REQUIRING_SYMBOL ( pxe_api_call );
REQUIRE_OBJECT ( pxe_preboot );
REQUIRE_OBJECT ( pxe_undi );
REQUIRE_OBJECT ( pxe_udp );
REQUIRE_OBJECT ( pxe_tftp );
REQUIRE_OBJECT ( pxe_file );
